Timing device



J. J. BRQWN TIMING DEVICE June 23, 1936.;

Filed March 26, 1934 2 Sheets-Sheet l Y wT/V w36., I J. J. BROWN l2,045,118

TMING DEVICE Filed March 26, 1934 2 Sheets-Sheet 2 INVENTOR /evw AORNEYS Patented June 23, 1936 UNITED STAT ES 04ans PATENT GFFICE 7Claims.

IIhe present invention relates broadly to a timing device and morespecifically-to an electrical timing switch.

'It comprises a device for timing'the operation of a mechanism,for'example, aphotographic printer, in such manner that the printer maybe controlled to be operative for a given time interval and also'wherein the` devicewmay be easily'rendered ineffective, so that itseffective operation may be `delayed under the will of an operatorwhenever it is desirable to Vretain -an intermediate controlfor asubstantial period of time.

The specific embodiment herein disclosed-*of the present invention is anelectrically controlled time switch for a printer-forphotographicpurposes. In lmaking prints or enlargements of photographs,it is desirable to controlthe effective time whenthe printing light isoperative upon the sensitized paper -or other printing' medium on whichthe photograph is beingprinted. In the commercial printing ofphotographsfwhere time of operation controls the 'speed of production,it is desirable that the photograph be printedwithin a few seconds,which means that the tolerances as to time of printing light are narrow,assuming, of course,that the source of light is of substantiallyconstant intensityfthat is; affraction Aof a second variation may meanan under-exposed or Van vover-exposed print, as-the'case mayfbe.

The preferred embodiment of the-present invention comprises a iluidfilledcylinder through which a weighted piston is adapted to be moved bygravity. The embodiment herewith, as will be hereinafter described indetail by referencel to the drawings, comprises asymmetric apparatuswith both ends of the cylinder effective for-the purposes desired. Thereis an electric switch at each end of thecylinder. These switches areconnected in series so that the opening of. either switch breaks thecircuit. Assuming the-Weighted piston to be at one end ofthe cylinder`and-the cylinder to be inverted, theweight of the piston will besupported by the iiuidin the cylinder conned beneaththe piston. Therelease of the fluid beneath the plstonwill control 'the'rate of' fallof the piston. This confined uid may be bypassed relative to thepistonin-such manner as to be permitted to flow frombeneath the pistonto a space above the piston. The by-pass is controlled by a suitableadjustable valve so that the rate of release of the fluid beneath thedescending piston, is controlled, 'thereby determining the 4timeinterval for the piston to descend the length of the cylinder. This.by-pass construction,

rthereby lighting the printing light.

(Cl. vW-34:)

whereby fluidisv lay-passed from one side of the piston to the other,provides a self-contained device. in which asuitable iiuid maybe sealedto insureagainst loss, and to prevent contamination y from dust anddirt. Any gas or liquid which does not vary a substantial amount inviscosity at nor- .mal room temperature variations is best suited forthe present invention. When the piston reaches the lower limit of itstravel, the weight ofthe piston operates, in the specific embodimentherewith, an electrical switch which opens a circuit and thereby cutsoff the printing light.

vIn the specific embodiment herewith, the cylinder is mounted upontrunnions and is adapted to be oscillated relative toits longitudinalaxis, so that the cylinder may alternately be inverted end for end. Thecontrol valve in the by-pass is set so that the time interval of thetravel of the piston from vone end of the cylinder to the othercorresponds tothe time a proper printing light is effective to properlyexpose a suitable sensitized paper or other medium through apredetermined,` negative. When fthe paper `and. negative are properlyassembled in a suitable printing ap- Y paratus, the operator inverts thecylinder. 'The piston which has been resting on the bottomof ythecylinder is now at the top and starts to -the cylinder. i The 'pistonagain travels downward-under the inuence of gravity and as soon Vasthefweight ofthe piston is released from the switch which it has opened,this switch closes, This light stays lighted until the piston hasdescended sufyciently to operate the other switch at the now lower endof the cylinder. These operationstare continued until the desired numberof prints are made when the next negative'is tested as to density. Thecontrol valve may be reset accordingly and the operations are repeated.The cylinder may be held in a horizontal position to retain the' lightlighted whenever this is desirable.

While thepresent invention is adapted to and isexplained with referenceto its operation in connection with'photographic apparatus, it is to beunderstoodthat'the invention may be useful for other ftiming operations.

It is recognized that the present invention may loe embodieduinv.structures differing from those specifically disclosed herewith, and,therefore, it is desired that the disclosure herewith shall beunderstood as illustrative and not in the limiting sense.

Fig. 1 illustrates a section of the device on line of Fig. 3.

Fig. 2 illustrates a section of the device on line 2 2 of Fig. 3.

Fig. 3 shows a section of the device on line 3--3 of Fig. 2.

Fig. 4 shows a diagrammatic illustration of the device as applied to alight adapted for photographic printing.

Fig. 5 illustrates a mechanism for oscillating the device by a footpedal.

Referring to the drawings and more especial- 1y to Fig. 1, the devicecomprises a body portion I having a cylindrical bore 2 with a tubularpassageway 4 in communication with the cylindrical bore 2 by means ofports 5 and 6. A Weighted piston 'I substantially fitting thecylindrical bore 2 is adapted to travel lengthwise therein under theinfluence of gravity when the body portion of the cylinder is inclinedsuiciently toward the vertical to cause gravity to overcome friction ofthe piston 'I on the side wall of the cylindrical bore 2. The ends ofthe cylindrical bore are closed by end plates 3. Preferably, the bodyportion I and the end plates 8 are formed of materials capable of beingjoined together in such manner as to provide a hermetic seal and in thepresent case, the body portion I and the end plates 8 are of metal andthe entire outside joint between the end of the body portion and the endplates 8 is closed or sealed by welding as at 9. This obviates anypossibility of the escape of the liquid I0 by evaporation or otherwise.This preferably comprises an oil or other fluid which is not subject tosubstantial expansion or contraction Within normal atmospherictemperature ranges and which does not substantially change in viscositywith such temperature changes. Each end plate 8 carries thereon asylphon member I. The sylphons are united to the end plates in suchmanner as to form a hermetic seal and in the present case, the sylphonspreferably are of metal and are Welded to the metal end plates 8. Thesylphons II allow expansion and contraction of the fluid due totemperature changes. The sylphons also comprise devices by whichterminal movements of the piston 'I may be communicated to an operatingpart such as an electrical switch. Cap members I2 are mounted upon theend plates 8 by suitable stub screws |4 or other convenient unitingmembers and these cap members may carry electrical switches I 5.Preferably, coil springs |6 extend between the cap members I2 and theends of the sylphons II to assist the movement of the sylphons away fromthe operating members I1 of the switches I5 when not being weighted downby the pistons. In order that trapped air may not interfere with thefree operation of the sylphon members, ports I8 may be provided throughthe cap members I2. A conduit I9 is provided for suitable electricalconnections to the electrical switches I5. Preferably, the body memberis provided at its central portion with a pair of oppositely disposedtrunnions 2li and 2|. The

trunnion 2| preferably is provided with an opening 22 leading to theconduit I9 to provide an outlet for the electrical wires leading to theswitches I5 so that these wires may be connected with a suitableelectrical circuit 24 which is under control of the switches I5.

The electric circuit 24 may include an electric lamp 25 and the circuitis supplied with current by a suitable source of electrical energy.'I'his electrical lamp 25 is the operating lamp for a photographicprinted 26. Photographic printers are well known in the art, and,therefore, for purposes of simplification, the photographic printer 26is merely illustrated diagrammatically.

The tubular passageway comprising the by-pass 4 is controlled by anadjustable valve. This adjustable valve may comprise a Valve head 21 ofsufficient size to completely block the passage-- Way 4 and to beprovided with a valve seat 28 so' that the passageway 4 is entirelyclosed when the valve head is completely seated. The valve head carriesa threaded extension 29 upon which is mounted an adjustment nut 30 whichbears against a valve casing 3|. A metallic sylphon 32 is hermeticallysealed to the valve head 21 and is also hermetically sealed to the valvecasing 3| as for example, by welding. A coiled spring 34 normally urgesthe valve head 2l toward the valve seat 28. This action of the spring 34is resisted by adjustment of the adjustment nut on the threadedextension 29 so that the valve may be set at any predetermined degree ofopening. The valve casing 3| is hermetically sealed to the body portionI of the cylinder as by welding as at 35. This construction of the valveis such that no leakage of liquid is possible through the valve casingto the exterior of the parts. In order to obviate any diiioulty inoperating the valve due to possible leakage around the valve head 2linto the casing 3|, a small port opening 35 is provided between thespace in the 'casing 3| and the by-pass 4.

'I'he device may be mounted in different ways for operation, butpreferably, is mounted in accordance with the illustration in Fig. 5wherein the trunnions 2i) and 2| are mounted to oscillate in bearingbrackets 31. A link 38 may be pivoted to the boss 39 (Fig. 2) on thebody portion I and is connected at the other end with the vertical armof a bell crank 4il mounted Ito oscillate in a frame bracket 4|. Anadjustable stop 42 adjusts the limit of movement of the bell crank 40 inone direction so that when the lower arm of the bell crank 4l) is incontact with the stop, the position of the parts will be such as tomaintain the body portion of the cylinder with the longitudinal axisthereof substantially vertical. A pedal 44 mounted on a pedal bracket 45is connected by a link 45 with a horizontal arm of the bell crank 4B. Aspring 41 normally maintains the forward end of the pedal raised and thelower arm of the bell crank in contact with the adjustable stop 42. Apivoted latch 48 may be provided in front of the pedal so that it may bemoved forward as the operator desires to hold the pedal in its lowerposition whenever this is desirable.

The operation of these parts is such that when the pedal 44 isdepressed, the link 38 pulls forward, thereby swinging the cylinder onthe trunnions and the momentum of the swinging movement carries thecylinder beyond dead center, so that when the pedal rises, the boss 3Sswings to the position 49 indicated in dotted lines in Fig. 5, and thelower arm of the bell crank 40 comes into contact with the adjustablestop 42 leaving the cylinder in inverted position. The piston descendsunder the influence of gravity and displaces the iluid beneath thepiston. The displaced fluid re-enters the chamber above the piston. Therate or speed of descent of the piston through a portion of its travelis determined by the setting of the control valve. A succeedingApressurezon'zthei pedalJSand-release thereofucauses.theylinderLtoktumfiend for end tolthe' position ,'showninlfullllinesinFigi. 5. 'Thus; it will--beseen .lthat ".-byz depressing fthe pedal-fand"releasinguthe 5 same the Y cylinderli may Abesuccessively 'L invertedfendlforrend Whereiitis' desirable thatthelight be-retained oncontinuously for` a"'substanti'al i length@ off. time; the. pedal. f ispushed down.. and -pivoted vvlatch` 48. I is :moved over..the -irend ofi the Yl pedal, thereby latching it in its lowerlposition. When thishappens, `the cylinderl :will assume an -inclined position aszindi'cated-xby the .'dotted line lll'in Fig. 5.

hen thecylinderK is.` inclined, .thel weightof the l piston f isremovednfromV :the sylphonwithzwhich the piston has beenin'.engagementandthe` spring |61zexpands the sylphon to. allowvthesWitch. `I5 v.todcl'ose 'While the inclination needibe` onlyslightly beyond ".thei` horizontal, .it shouldbe. sufflcient to allowthe release of the weight from the sylphon, and should be enough toinsure that the effect of gravity on the piston is in the direction totend to move the piston away from the sylphon, but not enough to causethe piston to move under influence of gravity alone.

When the cylinder is in this inclined position, the switches at bothends of the cylinder are closed and the light may be retained lighted solong as the cylinder is held in this inclined position. When it isdesired that operations shall be resumed, the latch 48 is released andthe cylinder will assume a vertical position as indicated in full linesin Fig. 5.

When the cylinder is in vertical position with the piston in the upperend of the cylinder, gravity operating on the piston causes the same todescend. By reference to Figs. l and 2, it will be noted that ports 6-6are located adjacent the ends of the cylindrical bore beyond the path ofmovement of the piston 1, while ports 5 5 are located within the path ofmovement of the piston. When the piston rst starts to descend, nosubstantial retarding action occurs because the fluid is freelyby-passed through the ports 5 and B adjacent the upper end of t-hecylinder. This permits the piston to move quickly away from the uppersylphon and permits the upper switch to close. Since the lower switch isalready closed, the circuit is now completed. As the piston movesdownward, it closes the upper port 5,

whereby fluid beneath the piston must now be bypassed through thecontrol Valve 21 and the travel of the piston is thereby retarded inaccordance with the setting of this valve, until the piston hasdescended suiiiciently to open the lower port 5,

at which time the fluid beneath the piston is bypassed rapidly from thelower port E through the lower port 5 which is now above the piston, andthe piston has reached the position indicated in Figs. 1 and 2. Thearrangement of the ports 5 and 6 eliminates further retarding action bythe valve 21 and permits the piston to move quickly toward the lower endof the cylinder, thereby exerting the full weight of the piston on thelower sylphon and switch mechanism to quickly open the switch I 5 in thelower end of the cylinder.

The ports 5-5 and 6-6 should each be at least of the same capacity asthe conduit 4. By this arrangement, it will be observed that during theinitial and nal travel of the piston, it is not substantially retardedin its movement, but as quickly as the piston closes the upper port 5,the further movement of the piston is under control of the control valve21, until the piston has descended sufciently to open the lower port 5at which time-the-.travel Yof 'the' piston iswagain lindependent of thecontrol valve 21. The piston 1 -is vin effect -afrnovable wallE dividingthe cylinder :into lLtwol chambers, -one of -which contains "iluid underslight compression-when theweight of--the 155 piston-is supported bythesaid fluid.

, Itwill be observed that the present device-de- -Ipendsfor its'timingfeatures upon fluid flow and .-is, therefore, *independentv of`mechanical clock mechanism or of electrical circuit characteristics,.10 and consequentlymay be operated in connection with any -type ofelectrical circuit either 'alternat- "ingor'direct current.' The presentdevice provides a simple and eflicient timing mechanism for theVpurposesintended. '15

AlWhat isv claimed is:

1; A device of the class described comprising a hermetically sealedcylinder, a piston movable byigravityfwithin said cylinder, sylphonmembers "hermetically sealed to the end walls of said cylin-fD der andbeingl adapted to be collapsed by 'the weight of said piston, electricalswitches operated by said sylphons, and means to control the speed ofmovement of said piston relative to said cylinder. 25

2. A hermetically sealed cylinder, a piston movable within saidcylinder, sylphons hermetically sealed to the end walls of saidcylinder, a bypass connected with the ends of said cylinder, saidcylinder being lled with a fluid, said uid being 30 adapted to iiowthrough said by-pass when said piston moves within said cylinder, avalve for controlling the rate of flow of fluid through said by-pass,said valve being operatively connected to a hermetically sealed sylphon,electrical switches 35 mounted within the sylphons carried by the endwalls of the cylinder, and means for oscillating said cylinder to causethe said piston to move therein.

3. A device of the class described, a chamber, 40 a piston slidable insaid chamber, said chamber containing a fluid, a conduit incommunication with both sides of said piston whereby the movement of thepiston displaces fluid from one side of the piston and replaces thefluid on the 45 opposite side thereof, control means for regulating therate of flow of said fluid through said conduit, and relief portsconnecting said chamber with said conduit so as to render said controlmeans ineffective when the piston passes a pre- 50 determined point inthe chamber.

4. A hermetically sealed cylinder, a piston movable by gravity withinsaid cylinder, bellows or diaphragms hermetically sealed into the endsof' said cylinder and adapted to having motion im- 55 parted thereto bythe movement of said piston, a by-pass connecting the ends of thecylinder, said cylinder being filled with a uid, said fluid beingadapted to flow thru said by-pass when said piston moves within saidcylinder, a control valve 50 for regulating the rate of flow cf saidfluid thru the by-pass, said control valve being operatively connectedto a hermetically sealed bellows or diaphragm, electrical switchesadapted to be operated by the movement of the first-mentioned 65 bellowsor diaphragms when Same are actuated by the movement of the piston, andrelief ports connecting said cylinder with said by-pass, said reliefports being so located in relation to the travel of the piston and inrelation to the loca- 70 tion of the said control valve that the iiuidbelow the piston is freely by-passed thru the nearest relief port to thespace above the piston independent of the action of the said controlvalve at 75 a time just prior to the piston reaching the end of itstravel.

5. A hermetically sealed cylinder, a piston movable by gravity Withinsaid cylinder, bellows or diaphragms hermetically sealed into the endsof Said cylinder and adapted to having motion imparted thereto by themovement of said piston, a by-pass connecting the ends of the cylinder,said cylinder being lled with a fluid, said fluid being adapted to owthru said by-pass when said piston moves within said cylinder, a controlvalve for regulating the rate of ow of said fluid thru the by-pass, saidcontrol valve being operatively connected to a, hermetically sealedbellows or diaphragm, and electrical switches adapted to be operated bythe movement of the mst-mentioned bellows or diaphragms when same areactuated by the movement of the piston.

6. A hermetically sealed cylinder, a piston movable by gravity Withinsaid cylinder, bellows or diaphragms hermetically sealed into the endsof said cylinder and adapted to having motion imparted thereto by themovement of said piston, a by-pass connecting the ends of the cylinder,said cylinder being filled with a fluid, said fluid being adapted to oWthru said by-pass when said v piston moves Within said cylinder, and a.control valve for regulating the rate of flow of said uid thru theby-pass, said control valve being operatively connected to ahermetically sealed bellows or diaphragm.

7. A hermetically sealed cylinder, a piston movable by gravity Withinsaid cylinder, bellows or diaphragms hermetically sealed into the endsof said cylinder and adapted to having motion imparted thereto by themovement of said piston, a l

by-pass connecting the ends of the cylinder, said cylinder being lledwith a uid, and said uid being adapted to ow through said by-pass whensaid piston moves within said cylinder.

JESSE J. BROWN.

